Please review my first MVVM project

Question

I'm trying to learn MVVM, so I made a simple WPF Application in C#, and since I am new to MVVM I was wondering if any of you can give me input on my code? Things I have done wrong, things I could have done better - maybe even things I've done right!
From my readme file:
Testing MVVM. Displays pictures based on radiobutton choices.
The button controls whether an image can be displayed. It also has text showing user if he can toggle images on/of.
Radiobuttons control which image to be displayed - but only displays the image if the button is clicked.
I'm open to all suggestions that might make me a better coder (as you can see I'm a little rusty when it comes to C# as well).
Here's my code: 
github.com/drberg/MVVMImageChooser

Answer 1

I think you're doing pretty well as you're new to mvvm and presumably wpf.
I suggest you take a look at mvvm light.  You can get it via nuget.
Choosing mvvmlight libraries only allows you to easily add it to an existing project or you can start a new mvvmlight project.  There's a template.
That gives you ViewModelBase you can inherit your viewmodels from.
With .net 4.5 there's callermembername and the implementation in mvvmlight uses this like the one you can find on msdn. 
If you don't want mvvmlight for whatever reason then you could inherit your viewmodels from this instead.
public class NotifyUIBase : INotifyPropertyChanged
// Very minimal implementation of INotifyPropertyChanged matching msdn
// Note that this is dependent on .net 4.5+ because of CallerMemberName
public event PropertyChangedEventHandler PropertyChanged;
public void RaisePropertyChanged([CallerMemberName] String propertyName = "")
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
That lets you remove the "magic strings" from property changed notification.
Thus
public BitmapImage Shape
get { return shape; }
set
shape = value;
RaisePropertyChanged();
Don't call your commands Button_Click
Most devs suffix the command with Execute for the method and CanExecute for the Boolean.
You've split code into view and viewmodel folders.
There are two schools of thought on this.
Some prefer to have a Views folder which then has a sub folder for like admin, another for sales etc etc
Then a folder within each with all the stuff related to a given view.
You often have a View, a view viewmodel, one or even several row viewmodels if there are a number of item controls. You can end up with quite a few bits and bobs which make up the one window.
You only have one view there.
I tend to have one window and numerous usercontrols rather than numerous windows.  The MainWIndow has a contentcontrol and the various views are swopped out.
If you've not taken a look at it already you might like:
http://social.technet.microsoft.com/wiki/contents/articles/28209.wpf-entity-framework-mvvm-walk-through-1.aspx
The second version, I've written the code and published two supporting articles explain techniques used.
Obviously, most
http://social.technet.microsoft.com/wiki/contents/articles/28597.wpf-keeping-your-mvvm-views-dry.aspx
The technique used to tell the viewmodel about errors the view finds is useful.
http://social.technet.microsoft.com/wiki/contents/articles/29777.wpf-property-list-editing.aspx
I've not yet written the main article yet.
MVVM light messaging is very useful and solves a number of those awkward bits you come across when doing mvvm.
http://social.technet.microsoft.com/wiki/contents/articles/26070.communicating-between-classes.aspx
Hope that helps.
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My latest Technet article - Dynamic XAML